Main incoming cable 10mm

[Don777]

Just spoken with DNO ukpowernetwork answer was you electrician should inspect load if you think load to high don't use she suggested increase fuse from 100amp to high or if you want 3phase 2400plus wat

 

[westie101]

I would have thought that most people would think that, having been give a 100A fuse, they could draw up to 100A without asking for special permission.

Yes they could, but it doesn't suggest that, say, 300 houses on an estate could all do so at the same time!!

Network design is done using diversity (shock horror just like installation design) so we would be looking for an average property (gas heating, immersion heater, choice of cooking fuel, normal appliances) with an ADMD (After Diversity Maximum Demand) of about 2kW (this we can confirm by looking at the MAD of a substation and dividing it by the number of houses it supplies).
That gives us the Network Constraint!
Start adding 9kW of Sauna, 10.5kW of shower and that figure WILL go up, which ultimately will overload the network.

If it were a DIYer they might have an excuse for not knowing but i would expect any decent electrical contractor to advise appropriately - or is it that because it isn't written in BS7671 or any of the advice attached they can ignore it and not advise their clients correctly and professionally.

Tell that to the guy up here that connected additional off-peak heaters in a shop taking the total to 28kW, did not get approval, did not uprate tails and got taken to court for £100,000 when the premises burned down!!

 

[ban-all-sheds]

is it that because it isn't written in BS7671 or any of the advice attached they can ignore it and not advise their clients correctly and professionally.

Not at all.

 

[JohnW2]

Network design is done using diversity (shock horror just like installation design) so we would be looking for an average property (gas heating, immersion heater, choice of cooking fuel, normal appliances) with an ADMD (After Diversity Maximum Demand) of about 2kW (this we can confirm by looking at the MAD of a substation and dividing it by the number of houses it supplies). That gives us the Network Constraint! Start adding 9kW of Sauna, 10.5kW of shower and that figure WILL go up, which ultimately will overload the network.

Some would probably say that was the Network Operator's problem, if they have not explicitly defined limits of the supply they had provided to a customer. If they defined a maximum average (over stated time period) after-diversity demand, then at least both they and customers would know where the goalposts were. As things stand, I'm not sure that even an electrician can necessarily be expected know whether a particular change to an installation requires telling/asking the DNO, unless the increased demand is clearly very large.

Kind Regards, John

 

[westie101]

As things stand, I'm not sure that even an electrician can necessarily be expected know whether a particular change to an installation requires telling/asking the DNO, unless the increased demand is clearly very large.

You do fully realise that this requirement has been on the various Terms and conditions for at least the last 40 years!! It is nothing new so if folk do not know they have been very badly trained and advised or are very unprofessional in their work etihc.

Sorry but for any qualified contractor to think that they can just connect anything to the DNO network is amazing and shows a huge and potentially dangerous hole in the system!

 

[DetlefSchmitz]

I read what John is saying as, it is not obvious what exact increase in load represents a reporting level. Also a number of small increases at different times may add up to a larger increase. But the level isn't defined.

 

[EFLImpudence]

I do wonder at the illogical nature and high-minded attitude of the large corporations.
We (large corporation) may do this but that doesn't mean you can (whatever) ...

Whilst I do not disagree with anything posted (and nothing personal) and have in the past advised customers wishing to fit a second or third large appliance to contact the supplier for advice, it does seem ridiculous to fit 100A fuses if the customer is not allowed to use this amount.

Would it not be sensible to fit 80A (and fit a sticker which denotes the actual rating of the fuse used and not the rating of the holder) as a rule and then, if permission is given for a larger usage, merely to then fit a 100A fuse.

The fact is 'we' may know the rules but I am confident in saying that the general public have no idea and a DIYer, who may be competent to fit these appliances or to install a larger 'replacement'. will have no knowledge that he is doing anything wrong.

To merely state that it is in the terms and conditions may be legally correct but does nothing to ensure the system is treated and used as intended.

 

[westie101]

I read what John is saying as, it is not obvious what exact increase in load represents a reporting level. Also a number of small increases at different times may add up to a larger increase. But the level isn't defined.

So ask the DNO and find out!!
It will vary upon location but generally we would advise any load over 3kW, any off-peak heating, any fixed motor above 1hp single phase and any welder of any size!
(if in rural areas with overhead supplies even 3kW can be significant on a 16 or 25 kVA transformer)
Don't forget also it is also about us preventing any interference with other customers supplies!!

I've dealt with pubs that decided to do meals, and installed a lot of cooking load in the kitchen without any notification - the worst I came across?? Peak loads of 163A on a 100A single phase supply.
All installed by an "electrician"

Oh and it isn't difficult, download a form from the internet and send it in or fill it in on line!!
We DON'T charge to check if the load is acceptable, only if we have to do work on the system.
Face it, with the hand wringing that goes on about having the correct certificates, if you don't have approval and there is a fire it might just be down to you!!

 

[westie101]

Nothing personal to anyone, but a lot on here spend time pushing the need to adhere to the likes of BS7671, no problem that is a definable design goal.

Why then do you get all defensive when it is pointed out to you that you need to adhere to other, very long standing, terms and conditions at your interface with the DNOs?

Within limits I have to comply with a lot of legislation and internal rules to do my job correctly.
As companies (large corporations) we have no choice, as if we step outside these limits (particularly legislation) we can be reported to regulatory authorities who will and do penalise us!
So we can only act correctly and advise (tell) others that they must behave correctly in their dealings with us, and the penalties for no doing so (and this is not a "the council might do something if they find out you have not complied with BS7671")
This is "we have legal duties imposed on us and will carry them out, if you cause us to break those duties we will use powers granted to us by legislation against you"!

OK we don't go in feet first (as don't councils, H.S.E. etc) and will seek to advise educate. If that doesn't work we will take it further!

 

[JohnW2]

You do fully realise that this requirement has been on the various Terms and conditions for at least the last 40 years!!

Exactly - IMO, no-one has attempted to improve this pretty ridiculous situation for decades.

It is nothing new so if folk do not know they have been very badly trained and advised or are very unprofessional in their work etihc.

Eh? Very badly trained and advised about what? Given a requirement which, by your own admission, is extremely 'wooly' and hasn't been improved or clarified for decades, how exactly can one train or advise people how to comply with it - except, as I said, in extreme cases (when common sense takes over, and training/advice is not required)?

Kind Regards, John

 

[westie101]

Answer this!

In the days when we were an Electricity Board and these terms still existed, why is it that almost 100% of add loads were correctly applied for?

Yet now we are privatised we are the big bad corporation that is making foolish rules that can be ignored or not bothered with as they make life difficult or you do not like them!

IGNORANCE OF THE LAW OR TERMS AND CONDITIONS OF A CONTRACT ARE NOT A VIABLE EXCUSE!

Someone trained/trains electricians this information is out there and should be passed on.

 

[JohnW2]

Oh and it isn't difficult, download a form from the internet and send it in or fill it in on line!!

True - but as far as the customers themselves are concerned, I wouldn't mind betting that only a tiny proportion have any idea of the 'requirement', hence would have no reason to go looking for a way of complying with it. Have DNOs ever made any attempt to publicise this to customers?

We DON'T charge to check if the load is acceptable, only if we have to do work on the system.

In the case of the (probably very) small minority of the public that know about any of this, I suspect that one of the deterrents is that they fear they could be charged a fortune for a 'supply upgrade' should it be decided that the load (or proposed load) was too high for the present supply.

Face it, with the hand wringing that goes on about having the correct certificates, if you don't have approval and there is a fire it might just be down to you!!

With respect, and also accepting that I'm generally the last person to do any such 'wringing', when that happens it is usually about compliance with clearly defined requirements, not ones that are so wooly that no-one can possibly know exactly what they mean without asking! It's a bit like having a sign which says just 'Speed Limit', and then threatening to prosecute someone for travelling at 47 mph, when he did not know that the sign was meant to indicate a 45 mph limit!

Kind Regards, John

 

[westie101]

Exactly - IMO, no-one has attempted to improve this pretty ridiculous situation for decades.

Maybe because the DNOs, the Regulators, the Governments, the Electricians Trade Bodies don't actually agree with you and believe the situation is acceptable!
If you and others don't like it, start writing to the above and your MPs!

 

[JohnW2]

Exactly - IMO, no-one has attempted to improve this pretty ridiculous situation for decades.

Maybe because the DNOs, the Regulators, the Governments, the Electricians Trade Bodies don't actually agree with you and believe the situation is acceptable! If you and others don't like it, start writing to the above and your MPs!

It's not 'me and others' who don't like the situation which is resulting in DNOs rarely being informed/asked about increased loads - it's seemingly the DNOs who don't like it! If they (the DNOs) want more notifying/asking to happen, then it really is they who should do some writing (hopefully about the actual details of the 'requirement' they would like to be complied with!).

Kind Regards, John

 

[westie101]

It's not 'me and others' who don't like the situation which is resulting in DNOs rarely being informed/asked about increased loads - it's seemingly the DNOs who don't like it! If they (the DNOs) want more notifying/asking to happen, then it really is they who should do some writing (hopefully about the actual details of the 'requirement' they would like to be complied with!).

No. No, No!
Every situation is different, there are a huge variations in supply characteristics so it would be dangerous to have minimum details.

The condition establishes the need so should be complied with, so if we start getting applications for very small loads we will deal with them, but along the way it means we won't miss the big ones!